Usage of 5whys in root cause analysis can be utilised when there is simple problem with less number of causes.5Ys are limited to simple approach, limited causes, it depends on individuals perspective, quick solution. Eg:Failure or Breakdown of Machine where 5whys can be applied. But when complex problem, multiple causes, strategic decision making involved we have to fish bone diagram, FMEA methods. Eg: increased lead time in call handling.